// Copyright (C) 2026 Kingsrook, LLC.
// SPDX-License-Identifier: Apache-2.0
import { createHash } from "node:crypto";
import { copyFile, lstat, mkdir, readFile, readdir, writeFile } from "node:fs/promises";
import path from "node:path";

// Packaging only. Never imports the compiler, executes source or installs packages.
// Root runs this with the approved exact Node executable after worker npm run build.
if (process.versions.node !== "24.22.2" || process.argv.length !== 4) {
  throw new Error("Use Node 24.22.2: build-compiler-image.mjs <absolute-worker-root> <new-absolute-output-root>");
}
const worker = process.argv[2];
const output = process.argv[3];
if (!path.isAbsolute(worker) || !path.isAbsolute(output) || output.includes("*") || output.includes(",")) {
  throw new Error("Absolute literal paths required");
}
const tsPackage = JSON.parse(await readFile(path.join(worker, "node_modules/typescript/package.json"), "utf8"));
if (tsPackage.version !== "6.0.3") throw new Error("TypeScript 6.0.3 required");
const libs = (await readdir(path.join(worker, "node_modules/typescript/lib")))
  .filter(name => /^lib\.[a-z0-9.]+\.d\.ts$/.test(name))
  .map(name => "node_modules/typescript/lib/" + name);
const files = ["package.json", "dist/compiler-entry.js", "dist/compiler.js", "dist/frames.js", "dist/protocol.js",
  "node_modules/typescript/package.json", "node_modules/typescript/lib/typescript.js", ...libs].sort();
if (files.length > 256 || libs.length === 0) throw new Error("Compiler closure size");
await mkdir(output); // Deliberately refuses any existing output; never overwrites a sealed image.
const root = path.join(output, "compiler");
await mkdir(root);
let total = 0;
const hashes = {};
for (const name of files) {
  const source = path.join(worker, name);
  const stat = await lstat(source);
  if (!stat.isFile() || stat.isSymbolicLink() || stat.size < 1 || stat.size > 16 * 1024 * 1024) throw new Error("Invalid compiler source file");
  total += stat.size;
  if (total > 64 * 1024 * 1024) throw new Error("Compiler closure bytes");
  const content = await readFile(source);
  hashes[name] = createHash("sha256").update(content).digest("hex");
  const target = path.join(root, name);
  await mkdir(path.dirname(target), { recursive: true });
  await writeFile(target, content, { flag: "wx" });
}
const manifest = JSON.stringify({ protocol: "qqq-typescript-image/1", nodeVersion: "24.22.2", typescriptVersion: "6.0.3", files: hashes }, null, 2) + "\n";
await writeFile(path.join(root, "compiler-manifest.json"), manifest, { flag: "wx" });
// Notices are adjacent to, never extra executable files inside, the closed tree.
const notices = path.join(output, "notices");
await mkdir(notices);
await copyFile(path.join(worker, "node_modules/typescript/LICENSE.txt"), path.join(notices, "typescript-LICENSE.txt"));
await copyFile(path.join(worker, "LICENSE"), path.join(notices, "worker-LICENSE"));
await copyFile(path.join(worker, "NOTICE"), path.join(notices, "worker-NOTICE"));
const nodeHash = createHash("sha256").update(await readFile(process.execPath)).digest("hex");
const evidence = { nodePath: process.execPath, nodeSha256: nodeHash, compilerRoot: root,
  manifestSha256: createHash("sha256").update(manifest).digest("hex"), files: files.length, bytes: total };
await writeFile(path.join(output, "compiler-image.json"), JSON.stringify(evidence, null, 2) + "\n", { flag: "wx" });
console.log(JSON.stringify(evidence));